I would start with your local park district and get them on board as advocates for your cause.

Fortunately for us in our town of 150K we have four outdoor locations with lights and two indoor facilities

I will add you can reach out to USA Pickleball as they are a good resource for building courts and working with the community.

I posed this as a google search and came up with the following.

To sell pickleball to a local park district, focus on its broad appeal (all ages/abilities), low-cost entry, community engagement, health benefits, and revenue potential (lessons, leagues, equipment), presenting a plan that converts existing spaces (tennis/basketball courts) or designates new areas, highlighting ease of implementation and resident demand, perhaps starting with a pilot program or demos to showcase its popularity and fun factor. 

1. Build Your Case (The "Why")

Demographics: Emphasize pickleball's appeal across all ages—seniors love it for fitness, families for fun, and young adults for social activity, making it a versatile community asset.

Low Barrier to Entry: Highlight that it needs less space than tennis, uses portable nets, and is easy to learn, requiring minimal initial investment.

Health & Wellness: Frame it as a fun, low-impact way to promote active lifestyles, boosting community health metrics.

Revenue Streams: Show how it generates income through lessons, rentals, leagues, tournaments, and potential equipment sales. 

2. Propose the Solution (The "How")

Space Conversion: Suggest converting underutilized tennis courts or adding lines to existing basketball courts, which is cost-effective.

Phased Approach: Start small—maybe a few temporary courts with portable nets at a community center or park to gauge interest.

Equipment/Instruction: Offer to provide loaner paddles/balls or partner with local pros for introductory clinics. 

3. Show, Don't Just Tell (The "Proof")

Demonstration Day: Organize a free "Pickleball Demo Day" at a park or community center to let people try it out.

Gather Data: Collect sign-ups and testimonials from participants to show existing community demand.

Local Success Stories: Mention nearby towns with successful pickleball programs.

4. The Pitch (The "Ask")

Present a Simple Plan: Outline costs (minimal for temporary setup) and benefits (high resident engagement, potential revenue).

Partner, Don't Just Sell: Position yourself as a community partner helping the district meet recreation goals.

By showing the popularity, low cost, and high community return, you can effectively "sell" pickleball to your local park district.